In the broadcast industry, audio and video recording and playback machines have been used to delay live broadcasts by several seconds to permit deletion of inappropriate language or gestures. These machines provide a fixed delay between the recording and playback of a given section of audio and/or video.
Many commercially available video cassette recorder (VCR) machines, i.e., videotape recorders with multiple heads, permit the user to play back recorded material immediately after it has been recorded, by positioning the play-back head after the record head. This enables the user to monitor the quality of the recording and watch the broadcast essentially live.
These machines do not allow the user to vary the delay between the recording and playback of segments of video.
More particularly, such conventional machines do not allow one to view material as it is being recorded, other than simultaneously or immediately after it has been recorded, as above. This imposes many inconveniences. For example, often one will anticipate arriving home at a particular hour, sometime after the commencement of a particular broadcast program one desires to watch. One must therefore set one's VCR to commence recording at the beginning of the program. If one then arrives a few minutes after the beginning of the program, one can watch the end of the program in real time, but cannot see its beginning until after the entire program has been recorded.
Similarly, often one will be watching a particular program when one must temporarily cease watching it, for example, to take a telephone call or the like. It would obviously be convenient to be able to record the program from that point forward, complete the telephone call, and simply watch the remainder delayed by the length of time of the interruption. However, no devices are now available which permit this facility. It also is not possible to employ two separate video cassette recorders to overcome these inconveniences.